Tendering properties of textiles dyed with yellow to orange vat dyestuffs by treatment with certain nitrogenous resins



Patented 10, 1948 s- PATENT OFFICE TENDERING PROPERTIES OF TEXTILES DYED WITH YELLOW TO ORANGE VAT DYESTUFFS BY TREATLIENT WITH CERTAIN NITROGENOUS-RESINS Albert Landolt, Riehen, Swltserland, assignor to Society of Chemical Industry in Basic, Basel, Switzerland, a Swiss firm No Drawing. Application May 9, 1944, Serial No. 534,802. In Switzerland January 8, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires January 6, 1983 8 Claims.

1 It is known that textile materials dyed with certain vat dyestufis, especially with certain yellow and orange dyestuffs, do not withstand thedine. Among such products those are especially suitable which have been formed in a reaction medium whose pH is not lower than '7. It has also been found that in particular cases it is of advantage to add metal salts, such as copper acetate, to the baths required by the above mentioned treatment.

The use of such reaction products, for example those of formaldehyde and compounds such as dicyanodiamide, guanidine, melamine or dicyanodlamidine, for fixing soluble products on sub- I by reason of their nature, are already fixed on strata, has already been recommended. .The 1 process may be effected by first of all treating the fiber with aqueous solutions of the reaction products of formaldehyde and the above described compounds in such a manner that after squeezing off, the fiber contains from 2 to 10 per cent. of the reaction product. The material is then dried, preferably at the usual temperature, for example between 7090 C. If the reaction products of formaldehyde are capable of being hardened, as is the case for 1 instance with the condensation products of melamine and formaldehyde, and if such hardening is to be effected, theproducts, after dry- 1 ing, are subjected to a heat treatment for example at 135-140" C. The heat treatment can also be omitted and drying can be effected mere- 1y for example at .70-90 C. provided care be taken that the pH of the liquid remaining on the fiber after squeezing is lower than 7. This hardening can be effected by the addition of small quantities of acid or of ammonium salts of stronger acids to the impregnating baths; if the reaction products themselves require an acid in order to be brought into solution, as is the case in Example 3 of the present specification, this acid also can bring aboutthedesired hardening on drying.

the fiber in a fast manner, an after-treatment of vat dyeings with fixing agents of this kind would have had no particular object. The method of working recommended in the present specification is therefore new and the peculiar resistance capacity of the textile materials attained thereby is entirely surprising especially because a condensation product, for example from dimethylolurea produced on the fiber, does not exhibit such an effect.

It has further been found that this treatment not only entails the protection of textile ma= terials dyed with vat dyestuffs, but also improves the fastness to light of these dyeings. This latter phenomenon can be ascertained not only in yellow vat dyestuffs, but it is of quite general na- 'ture and occurs in dyeings produced with vat dyestuffs of the most varied constitutions and shades.

The following examples illustrate the invention, but are not to be regarded as limiting it in any way:

Example 1 A cotton fabric is dyed in the usual manner with 0.5 per cent. of the yellowvat dyestuif of Example 1 of U. S. A. Patent No. 1,090,621 and then after-treated in the following manner:

4 kg. of a water-soluble reaction product of formaldehyde and dicyanodiamidine are introduced, while stirring, into 4 liters of water of 35 0., whereby a thick paste is formed. 16 liters of water of 35 C. containing 120 cc. of formic acid are then introduced into this paste, while stirring. When the solution is clear, it is made up to liters by addition of water. The dyed cotton is impregnated in this solution. For this purpose the fabric is passed through the solution in the padding machine, squeezed off and dried on the stretching frame.

The cotton fabric treated in such a manner showed the following result when exposed to light during 2 summer months:

. Moreover, the fastness to light of the treated fabric is essentially improved.

The water-soluble reaction product of dicy-- anodiamidine and formaldehyde can be prepared for example by allowing formaldehyde to act on dicyanodiamidine according to the method described in U. S. Patent No. 2,093,651, Example /1).

Example 2 A cotton satin dye with 1.3 per cent. of the ternary condensation product from 1 mol. of cyanuric chloride, 2 mols. oi Z-amino-anthraquinone and 1 mol. of aniline, was after treated as described in Example 1 in a bath containing 40 grams of copper acetate in addition to the indicated substances. After exposure to light the following result was obtained:

Not Exposed Exposed to to light light Tensile strength of the fabric which Per cent Per cent has only been dyed 100 19.4 Tensile strength of the alter-treated fabric 100 66.2

Example 3 A cotton fabric dyed with 0.5 per cent. of the orange vat dyestuir No. 1096 of the Colour Inidex, is after-treated in a solution containing per liter A hydrophobe reaction product of melamine and formaldehyde grams 40 Formic acid cc 13.5

.Copper acetate grams squeezed through the padding machine so as to contain 70 per cent. of the solution, and dried.

The hydrophobe reaction product is dissolved in three times its quantity of hot water and then poured into water acidified with formic acid, whereby a clear solution is obtained. The result of the exposure to light is then following:

Not exposed Exposed to to light light Tensile strength of the fabric which Per cent Per cent has only been dyed 100 Tensile strength of the after-treated rio 100 62. 5

Here, too, the iastness to light of the dyestufl has been essentially improved.

The hydrophobe melamine-formaldehyde reaction product applied here has been prepared as follows:

1 mol. of melamine is condensed in a reflux apparatus at 80-90 c. with 3 mols. of an aqueous formaldehyde solution of per cent. strength until a sample of -the condensation solution, cooled to room temperature and diluted with the three fold quantity of water, remains clear (French Patent No. 811,804)

Example 4 4 lowing dyestuffs can also be improved: blue dye Colour Index No. 1183; 5: 7: 5 7 tetrachloroindigo; 4: 4 dimethyl-G: 6 dichlorothioindigo: violet dye Colour Index No. 1104.

What I claim is:

1. Process for improving the properties of textile materials dyed with vat dyestuffs, which comprises treating textile materials dyed with yellow to orange dyeing vat dyestufls which render the textile tender upon exposure to light with aqueous solutions of reaction products of formaldehyde and compounds which contain, on the one hand, at least once and at the most three times the atom grouping wherein the free valence of the carbon atom is bound to a nitrogen atom, and, on the other hand, at the most one oxygen atom in an atom grouping 1 i=0 ILH:

which compounds contain at least two and at the most three carbon atoms. at least four and at the most six nitrogen atoms, and hydrogen as the only additional element; said reaction products having been formed in a reaction medium whose pH is not lower than 7, and subjecting the textile materials to a drying process at a pH smaller than 7.

2. Process for improving the properties of textile materials dyed with vat dyestuffs, which comprises treating textile materials dyed with yellow to orange dyeing vat dyestuffs which render the textile tender upon exposure to light with aqueous solutions of reaction products of formaldehyde and dicyanodiamidine formed in a reaction medium whose pH is not lower than 7, and subjecting them to a drying process.

8. Process for improving the properties of textile materials dyed with vat dyestuffs, which comprises treating textile materials dyed with yellow to orange dyeing vat dyestuffs which render the textile tender upon exposure to light with aqueous solutions of reaction products of formaldehyde and melamine formed in a reaction medium whose pH is not lower than 7, and subjecting them to a drying process.

4. Textile material dyed with a vat dyestuff and treated according to the process recited in claim 1, said material being characterized by a markedly increased resistance to tendering upon exposure to light as compared with similarly dyed but untreated textile material.

5. Textile material dyed with a yellow to orange dyeing vat dyestuif and treated according to the process recited in claim 2, said material being characterized by a markedly increased resistance to tendering upon exposure to light as compared with similarly dyed but untreated textile material.

6. Textile material dyed with a yellowto orange dyeing vat dyestuif and treated according to the process recited in claim 3, said material being characterized by a markedly increased resistance to tendering upon exposure to light as compared with similarly dyed but untreated textile material.

ALBERT LANDOLT.

(References on following page) 2,495,591 5 nnmmcns crmn Number The following references are of record in the tile or this patent: 1'734'516 UNITED sums PATENTS a 2:364:726 Number Name Dete 2375424 2,169,545 Wldmer Aug. 15, 1939 246118 2,197,357 Widmer Apr. 16, 1949 2,185,143 Crossley Dec. 26, 1939 1,909,221 Paquin May 16, 1939 3:32 2,253,457 Whittaker "Aug. 19, 1941 Wldmer June 22, 1943 Home Date Wldmer Sept. 21. 1937 Rivet July 5, 1938 Foulds Nov. 5, 1929 Landolt Dec. 12, 1944 MacGrecor May 1, 1945 Dreyfus June 13, 1939 FOREIGN PATENTS Country Date Great Britain Jan. 26, 1944 

